Added Essential Infrastructure as Code

Hi,

Stjepan from Manning here. I thought this title might be a good match to your list. Thank you for considering it.

Best,

README.md

@@ -219,6 +219,7 @@ Name | Comments
 [The Phoenix Project](https://www.amazon.com/Phoenix-Project-DevOps-Helping-Business/dp/1942788290) | DevOps explained through a story of a fictional company on the brink of a failure
 [The DevOps Handbook](https://www.amazon.com/dp/1942788002) |
 [Google SRE books](https://landing.google.com/sre/books) | Very detailed books on the theory and also practice of SRE
+[Essential Infrastructure as Code](https://www.manning.com/books/essential-infrastructure-as-code) | VBook about automating software infrastructure by capturing desired configurations as a set of scripts.
 
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